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Franklin Aldridge posted an update 6 months, 3 weeks ago
PURPOSE To analyze the implications of different reference points on the read-out of epithelial thickness mapping. METHODS A simulation for changing the reference point from normal-to-the-surface tangent to parallel vertical sections quantifying its effect on the read-out of epithelial thickness mapping has been developed. The simulation includes a simple modeling of corneal epithelial profiles and allows the analytical quantification of the differences in the read-out from normal-to-the-surface tangent to parallel vertical sections epithelial thickness mapping. Defactinib RESULTS The difference in the read-out between parallel vertical sections and normal-to-the-surface tangent epithelial thickness mapping increases for steeper corneas, but it is not largely affected by asphericity. The difference increases for thicker epithelia. CONCLUSIONS The reference point for determining the readout of epithelial thickness mapping should be taken into account when interpreting output. Using conventional epithelial thickness map readings (normal-to-the surface tangent) in transepithelial ablations (representing close to parallel vertical sections) may result in induced refractive errors that can be quantified using simple theoretical simulations, because the center-to-periphery progression of the corneal epithelial profile deviates from the progression of the ablated one. Adjustments for the epithelial thickness read-out or, alternatively, for the target sphere can be easily derived. . Copyright 2020, SLACK Incorporated.PURPOSE To compare optical coherence tomography (OCT) and Scheimpflug curvature and aberrations of the Bowman’s layer before and after removal of the epithelium. METHODS Bowman’s layer was mapped with OCT (Optovue Inc., Irvine, CA) before and after removal of the epithelium in normal eyes undergoing photorefractive keratectomy (n = 14) and keratoconic eyes undergoing corneal cross-linking (n = 25). The anterior corneal surface before removal and the underlying Bowman’s layer after removal of the epithelium were also mapped with Pentacam (Oculus Optikgeräte, Wetzlar, Germany), and the surface aberrations with ray tracing were computed. RESULTS The agreement of OCT curvatures before and after removal of the epithelium was excellent (intraclass correlation coefficient = 0.9). A similar trend was seen between OCT and Pentacam after removal of the epithelium. The agreement of surface wavefront aberrations of the Bowman’s layer before and after removal of the epithelium was excellent (ICC = 0.9) between the devices for keratoconic eyes. However, this agreement was relatively inferior in normal eyes (ICC less then 0.5). CONCLUSIONS The virtual OCT curvature and aberrations of the Bowman’s layer agreed well with its actual magnitudes on removal of the epithelium in the keratoconic eyes. In normal eyes, the agreement was inferior for aberrations but not for curvature. . Copyright 2020, SLACK Incorporated.PURPOSE To analyze clinical outcomes of cataract surgery with implantation of a toric intraocular lens (IOL) and to evaluate the effect of capsular tension ring (CTR) presence or absence on the rotational stability of implanted IOLs and postoperative refraction. METHODS This cohort study included 64 eyes of 41 patients who underwent uneventful cataract surgery with implantation of a toric IOL (enVista toric MX60T; Bausch & Lomb, Rochester, NY) to correct preoperative corneal astigmatism. In 30 eyes, a CTR (11 SR model; Videris s.r.o., Prague, Czech Republic) was co-implanted. Analyzed parameters were refraction, visual acuity, and misalignment of toric lenses. RESULTS The mean patient age was 67 years (range 42 to 89 years) and the mean follow-up period was 5 months. Mean manifest astigmatism improved from -1.53 ± 1.15 diopters (D) preoperatively to -0.40 ± 0.61 D postoperatively (P less then .001). Postoperative uncorrected distance visual acuity was 0.10 ± 0.13 logMAR (20/25 Snellen). Mean absolute IOL misalignment was 3.70° with CTR and 3.85° without CTR (P = .683). In eyes with an axial length of 24 mm or greater, IOL axis matched the planned axis in 90.5% of eyes with CTR and 81.8% of eyes without CTR (P = .964). Four eyes (6.25%) needed additional surgical IOL rotation. CONCLUSIONS In eyes after cataract surgery with implantation of a toric IOL, there were no significant differences in the rotational stability of the lens with respect to the presence or absence of CTR. In eyes with an axial length of 24 mm or greater, better IOL alignment was observed in the group with CTR. . Copyright 2020, SLACK Incorporated.PURPOSE To identify independent factors associated with postoperative satisfaction after refractive lens exchange with an extended depth of focus intraocular lens (EDOF IOL). METHODS Patients who underwent a refractive lens exchange with bilateral implantation of the AT LARA 829MP IOL (Carl Zeiss Meditec, Jena, Germany) and attended the 3-month follow-up visit were included in the analysis (N = 351 patients). Demographics, preoperative and postoperative clinical parameters, and patient-reported outcomes were used in a regression model to determine predictors of 3-month postoperative satisfaction. RESULTS The mean age of the study group was 58.2 ± 7.0 years (range 45 to 79 years) and the mean preoperative sphere ranged between -12.50 and +6.75 diopters (D). At 3 months postoperatively, 86.6% of patients were very satisfied or satisfied with outcomes and 93.2% would recommend the procedure to their family or friends. Of all patients, 90.6% achieved binocular uncorrected distance visual acuity of 20/20 or better, 92.0% achieved binocular near vision of 20/50 or better, and 85.5% of eyes were within ±0.50 D of emmetropia. Logistic regression identified postoperative dry eye symptoms, binocular near and distance visual acuity, and glare symptoms as significant independent factors affecting patient satisfaction. CONCLUSIONS Several factors were independently predictive of postoperative satisfaction after EDOF IOL implantation and addressing these may further improve patient satisfaction with the procedure, specifically, proper management of early symptoms of dry eye, ensuring good refractive predictability to maximize unaided vision, and counseling patients about the possibility of visual phenomena in the early postoperative period. . Copyright 2020, SLACK Incorporated.